Mechanical & Thermal Modelling and Simulation Engineer
Date: 6 Feb 2026
Location: Seraing, Belgium
Company: John Cockerill
John Cockerill, enablers of opportunities
Driven since 1817 by the entrepreneurial spirit and thirst for innovation of its founder, the John Cockerill Group develops large-scale technological solutions to meet the needs of its time: facilitating access to low carbon energies, enabling sustainable industrial production, preserving natural resources, contributing to greener mobility, enhancing security and installing essential infrastructures.
Its offer to businesses, governments and communities consists of services and associated equipment for the sectors of energy, defence, industry, the environment, transports, and infrastructures. With more than 8,000 employees, John Cockerill achieved a turnover of € 1.417 billion in 2024 in 28 countries, on 5 continents.
Are you ready to contribute to high-impact, international energy projects shaping the future of low-carbon industry?
Driven since 1817 by the entrepreneurial spirit and thirst for innovation of its founder, the John Cockerill Group develops large-scale technological solutions to meet the needs of its time: facilitating access to low-carbon energies, enabling sustainable industrial production, preserving natural resources, contributing to greener mobility, enhancing security, and installing critical infrastructures.
Its offer to companies, States and communities consists of services and associated equipment for the sectors of energy, defence, industry, the environment, transports, and infrastructures.
With over 8,000 employees, John Cockerill achieved a turnover of €1.417 billion in 2024, operating in 28 countries across 5 continents.
Within this framework, John Cockerill Energy plays a key role in the energy transition by delivering advanced solutions for power generation, heat recovery, hydrogen, renewable energy and industrial decarbonisation, supporting customers worldwide in building a more sustainable energy future.
Why join John Cockerill Energy?
- Meaningful impact: contribute to energy projects directly supporting decarbonisation and energy efficiency.
- Global reach: collaborate with multicultural teams and work on complex projects worldwide.
👉 Discover our international talent: https://www.youtube.com/watch?v=CvUiEakGcsQ&t=72s - Supportive environment: benefit from a culture of flexibility, autonomy and work-life balance.
- Engineering & decision centers on the same site: evolve in an agile, engineering-driven environment enabling fast and informed decisions.
Because the energy transition requires reliable, efficient and sustainable technologies, John Cockerill Energy continuously innovates to deliver solutions combining performance, safety and environmental responsibility.
Your role
Your responsibilities will cover a wide range of activities such as thermodynamics, mechanics, fluid mechanics, strength of materials, welding, and pressure equipment manufacturing, related to the sizing and technical development of products in this sector, including:
- Performing calculations using 3D modelling through FEA (Finite Element Analysis) and CFD (Computational Fluid Dynamics);
- Ensuring the continuous monitoring, updating, and development of our thermal modelling tool VALI, as well as the continuous improvement of the source code of our equipment;
- Implementing fatigue calculation models and residual lifetime assessment models.
Your key responsibilities
- Contribute to the preparation, coordination or execution of energy-related projects or technical activities
- Collaborate with internal teams and external partners to ensure quality, consistency and timely delivery
Your team
You will join a multidisciplinary and collaborative team, working closely with engineers, designers, project managers and business stakeholders.
The work culture encourages knowledge sharing, teamwork and continuous improvement, supported by a management style based on trust, autonomy and clear communication.
Your profile
Experience & technical skills
- You hold a higher technical education degree (Master’s level);
- Either in electromechanical engineering, preferably with a specialization in energy systems, or equivalent experience;
- Or in numerical modelling, with solid foundations in strength of materials and thermodynamics;
- You are perfectly fluent in French and have a good command of English, both spoken and written;
- You are proficient in Microsoft Office software, including writing Excel macros;
- Knowledge of programming languages such as Python, C#, Matlab, etc. is required;
- You have initial professional experience in a design office, preferably in the fields described above; if not, you are motivated to develop your skills in these areas;
- Experience in fatigue analysis and residual lifetime assessment of installations or components is considered an asset;
Personal & behavioral skills
- You are attracted to design office work, which requires meticulousness, a systematic approach, and teamwork;
- Reading standards, codes, directives, and regulations does not discourage you;
- You are eager to work within a young and dynamic team;
- You are willing and able to travel abroad for short stays for training sessions or collaboration with other John Cockerill entities.
What we offer
At John Cockerill, we deeply value your contribution:
- Attractive salary package with many extra-legal benefits: company car, meal vouchers, flat-rate expenses, hospitalization/life/death/guaranteed income insurance, variable remuneration ranging from 0–25% of your gross annual salary, profit-sharing scheme based on progress and results
- Flexible work arrangements, with 1–2 days of remote work per week after training
- Comprehensive onboarding: a 6-month training with plenty of learning opportunities
- Career development: regular reviews, large catalogue of training, and career progression
- International opportunities: potential to evolve within your sector, across different sectors or businesses, and across different regions
- 31 days off
- The position is based in Seraing
The recruitment process
Ready to take on this exciting challenge and contribute to the future of energy?
What are the next steps?
- First interview with Stephanie Beghein, Talent Acquisition
- On-site meeting with Denis Gathoye
- Final interview
Is it a match between you and John Cockerill? May this collaboration begin!
Want to find out more about John Cockerill Energy’s exciting projects?
👉 https://www.youtube.com/watch?v=rMTyXXW7C-U
This is not the opportunity you're looking for?
You can also join our talent pool and be contacted for other positions in the future:
John Cockerill offers you career and development opportunities within its various sectors in a friendly working environment.
Do you want to work for an innovative company that will allow you to take up technical challenges on a daily basis?
We look forward to receiving your application and to meeting you!
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